Effect of Different Inlet/Outlet Port Configurations on the Thermal Management of Prismatic Li-Ion Batteries

The performance and life cycle of Li-ion batteries are governed by the maximum temperature and uniformity of temperature distribution in the battery pack, and an efficient thermal management system is highly desired to keep the operating temperature of the battery pack within safe operating limits. Air cooling has received extensive attention in the area of battery thermal management. However, performance intensification of air-cooling modules is essential while keeping the simplicity of design to satisfy the weight and space constraints of electric vehicle (EV) applications. In the current work, efforts have been made to design a simple and generalized air-cooling module for efficient thermal management of Li-ion batteries. The current work explored the effect of two common air flow configurations: side inlet and side outlet (SS) and side inlet and front outlet (SF), with different number of inlet/outlet ports (single inlet and single outlet, single inlet and two outlets, two inlets and single outlet, and two inlets and two outlets) on the thermal and hydraulic performance of Li-ion battery pack. Subsequently, a new design of battery module with an open outlet port is proposed. It is observed that the way fluid leaves the cooling module significantly influences the flow and temperature distribution uniformity of the battery pack. Significant improvement in the fluid flow distribution and lower temperature fluctuation are maintained by the SF designs as compared to the SS designs. Among all SS designs, only SS-Ib at V_in ≥ 5.6 m/s and SS-IV at V_in ≥ 4.8 m/s are found suitable for the thermal management of Li-ion battery pack, whereas all SF designs maintained desired T_max and ΔT_max conditions at V_in ≥ 4.8 m/s. Furthermore, the new design (SF-V) with an open outlet results in the reduction of T_max by 7 °C and ΔT_max by 64.5% as compared to base design (SS-Ia) at the same pressure drop penalty.